The present invention is directed to a multi-part valve body for discharging a fluid from a container, such as a flexible collapsible container, while preventing back flow into the container, particularly of contaminants. The valve assembly is formed of an axially extending valve body with a first or inlet end part containing a flow passage, a second or outlet end part also containing a flow passage and a third or intermediate part between the first and second end part with the third part being imperforate. An elastomeric sheath tightly encloses the three parts. The elastomeric sheath can expand outwardly permitting the different parts to separate in the axial direction and affording a flow of fluid from the inlet end part to the outlet end part within the elastomeric sheath.
In dispensing sterile fluids from a container, especially when the container has an extended use lifetime, it is important to prevent any back flow of contaminants into the container during and following the dispensing operation. Contamination from the ambient atmosphere may include microorganisms, atmospheric gases, moisture, dust and the like. If a sterile fluid is contaminated it can affect its quality, potency and even the safety of the fluid.
If a container of sterile fluid has a one-time use and is not intended to be dispensed over an extended period of time, the problem of contaminants entering the container usually does not exist.
Sterile fluid may involve a variety of products, such as drugs, beverages, cosmetics and the like. The fluid may be a liquid, lotion, cream, gel, powder, gas or the like.
The present invention is an improvement on the valve assembly disclosed in the U.S. Pat. No. 4,846,810 hereinafter referred to as the ReSeal Valve. In the ReSeal Valve a unitary valve body was used enclosed within an elastomeric sheath. While the ReSeal Valve is effective in maintaining the sterility of a fluid within a container, the formation of the flow passages through the valve body can increase its cost.